Ferguson, 71, is the longest-serving manager in English football having been at the United helm for a trophy-laden 27 years.

However, speculation about his possible retirement has regularly appeared in recent years and returned in the wake of the Premier League champions' confirmation that Ferguson requires surgery on his hip this summer.

Those rumours gained momentum on Tuesday, with a United golf day allegedly overshadowed by speculation about the Scot's future.

Both The Times and The Telegraph cite sources close to the first-team squad saying that the United players have been told to ready themselves for a "significant announcement" from their manager.

As of Tuesday night, the club had failed to respond to requests to confirm or deny the reports about Ferguson's future, although New York Stock Exchange rules mean the club will have to inform them of such a significant development. If continued news speculation does affect trading, United may have to issue guidance to investors.

Bookmakers did close markets on Ferguson's retirement, as well as David Moyes being his immediate successor.
It has also been mooted, however, that any announcement may just see a stand-in installed until the 71-year-old recovers from a July hip operation around the end of August.

United have long been attempting to put a framework in place so that the succession is as smooth as possible - and avoids the chaos of the post-Matt Busby era, when the legendary manager moved into a director of football role before later returning to take the managerial reins.

However, there have already been informal meetings with potential future candidates. Ferguson, David Gill and one of the Glazer family met Pep Guardiola in New York in October, before the Catalan agreed to take over at Bayern Munich.

Despite Ferguson's personal enthusiasm about the future appointment of Guardiola, he is known to have been a huge admirer of Moyes and feels he has many of the qualities necessary to take over at Old Trafford.

Jose Mourinho is not expected to be in the frame, though, with a high-ranking Stamford Bridge source telling ESPN that the the Portuguese is "virtually certain" to replace Rafael Benitez in the next two months, and there is too little leverage room for United to attempt any kind of late high-profile coup. However, it is understood that Roman Abramovich is balking at paying any buy-out clause, which may leave an opening for United.

Ferguson announced his intention to retire in 2002 before changing his mind and going on to win a further six Premier League titles, with this year's championship crown his 13th in all with the club.